Seropositivity of hepatitis C, hepatitis B and HIV in chronically transfused ß-thalassaemia major patients.

The purpose of this study was to determine the frequency and trend of transfusion transmitted infections (TTI) in chronically transfused ß-thalassaemia major (TM) patients with reference to the duration of transfusions. A cross-sectional study was done on 160 ß-TM patients and 5517 healthy blood donors to find out the prevalence of HCV, HBV and HIV infections. Out of 160 patients, 21 cases (13.1%) were anti-HCV positive, 2 (1.25%) were HBsAg positive. HIV antibodies were not detected in any sample. However, 109 (1.9%) and 104 (1.8%) of 5517 blood donors were positive for HCV and HBV respectively. No donor showed HIV antibodies. Anti-HCV was positive in 9/111(8.4%) thalassaemics (< 10 years of age) while 11/49 (22%) [> 10 years of age] showing significant difference (p = 0.005) among the two groups. For the past 10 - 12 years the screening of blood has reduced the magnitude of the disease significantly as shown by the trend in two age groups. Further improvements need to be done to implement uniform screening throughout the country.

Molecular epidemiology of ß-thalassemia in Pakistan: far reaching implications.

ß-thalassaemia, an autosomal recessive hemoglobinopathy, is one of the commonest genetically transmitted disorders throughout the world. Collective measures including carrier identification, genetic counseling and prenatal diagnosis are required for preventing ß-thalassemia. To achieve this objective, Identification of the spectrum of genetic mutations, especially for various ethnic backgrounds in Pakistan is necessary. Therefore, we designed a cross sectional prospective study to identify the frequency of various gene mutations in different ethnic groups of Pakistan. Over a 5-year period, DNA from 648 blood samples [including specimens of chorionic villus sampling (CVS)] were analyzed for the twelve most common ß-thalassemia mutations found in the Pakistani population by a Multiplex amplification refractory mutation system (ARMS). The most common mutation identified was Intervening Sequence 1-5 (IVS 1-5 (G-C)); accounting for 40.89% mutated alleles, and was represented in all ethnic groups. 15.7 % of the ß-thalassemia alleles were found to have Frameshift 8-9 (Fr 8-9) as the second most common mutation Other common genetic defects responsible for ß-thalassemia: IVS 1-1 (G-T) was found in 8.17%, Codon-30 (Cd-30 (G-C)) 8.02%, Codon-5(Cd-5 (-CT)) contributed 2.16% and Deletion 619 base pair (Del 619bp) affected 11.11% were found in Pakistan. This large study adds to the pre-existing data in Pakistan. Knowledge of the predominant mutation in a given ethnic group will not only help in developing a short panel of (population-specific) primers of mutations thereby providing a cost-effective method for prenatal diagnosis and also help the clinicians to counsel regarding blood transfusion regimen/ pregnancy termination.